The cabin of modern aircraft is equipped with a plurality of smoke detectors which allow a fast and reliable detection of smoke and thus significantly reduce the risk of fire on board the aircraft. Typically, the smoke detectors are installed in a ceiling region of the aircraft cabin. At certain operational states of the aircraft, for example during ground operation of the aircraft at hot ambient temperatures and/or intense solar radiation, the aircraft outer shell is heated while the interior of the aircraft cabin is cooled by means of the aircraft air conditioning system. This may cause the formation of air layers having different temperatures within the aircraft cabin. In particular, due to the injection of cool air conditioned air into the aircraft cabin through air outlets disposed in a sidewall region or a floor region of the aircraft cabin, a layer of cool air may form in a lower region of the aircraft cabin, whereas a layer of warm air may be present in the ceiling region of the aircraft cabin.
A warm air layer prevailing in the ceiling region of the aircraft cabin may hinder or at least delay a rising of smoke, which is generated or present in the lower region of the aircraft cabin, to the ceiling region of the aircraft cabin due to thermal convection. Therefore, additional smoke sensors with corresponding electrical connections have to be provided in the lower region of the aircraft cabin. Alternatively or additionally thereto, suitable ventilation means, for example in the form of fans or blowers, may be used for dissolving undesired air layer structures which may form within the aircraft cabin.